big-rat/lib/ctz.js

A big integer rational number

'use strict'

var db = require('double-bits')
var ctz = require('bit-twiddle').countTrailingZeros

module.exports = ctzNumber

//Counts the number of trailing zeros
function ctzNumber(x) {
  var l = ctz(db.lo(x))
  if(l < 32) {
    return l
  }
  var h = ctz(db.hi(x))
  if(h > 20) {
    return 52
  }
  return h + 32
}